1. Field of the Invention
The invention relates in general to a scanning device and a method thereof, and more particularly to a scanning device detects the presence of an object at a reference origin and a method thereof.
2. Description of the Related Art
Referring to FIG. 1, a perspective of a conventional scanning device is shown. The scanning device 100 includes a scanning platform 110 and an optical chassis 130. An object 190 is placed on the scanning platform 110.
The scanning device 100 includes a first detecting unit 120 and a second detecting unit 140 for determining size of the object 190. Referring to FIG. 2A, a perspective of a first detecting unit and a second detecting unit of FIG. 1 determining the size of an object is shown. The first detecting unit 120 is disposed in response to a size range A1 (such as A4 size). The second detecting unit 140 is disposed in response to a size range A2 (such as letter size).
Referring to both FIGS. 2B and 2C, two perspectives of an object placed on a scanning platform of FIG. 1 are shown. The size of the object 190 is similar to the size range A1. As indicated in FIG. 2B, when the object 190 is aligned with a reference origin 110′, the object 190 will be detected by the first detecting unit 120, the scanning device 100 will scan the object 190 as if scanning an A4 size document, and the optical chassis 130 will capture a complete image of the object 190.
As indicated in FIG. 2C, when a position of the object 190 on the scanning platform 110 is deviated from the reference origin 110′, the object 190 will still be detected by the second detecting unit 140, and the scanning device 100 will scan the object 190 as if scanning a letter size document. Thus, the optical chassis 130 cannot capture the complete image of the object 190.
According to the above disclosure, when the position of the object 190 on the scanning platform 110 is deviated from the reference origin 110′, an image-capturing range will be erroneously defined and caused great inconvenience to the user.